I see its fixed but did it ever backfire when you revved it at all? Mine stalls when I let off the gas going slow and sometimes when I first try to hit the gas. Rev then cant recover. Fresh tune up n iac. Alt is 2yrs old. Cant wheel when it don't want to take off or stop w out stalling

 

Mine never backfired but sometimes when it started I had to keep on the gas to keep it running. If I let off slightly the engine would misfire (rpms would jump around a few 100's) and would die instantly. I would try to start again but it would only crank because it lost spark.

If the crank sensor is bad it will essentially tell the ECU not to give spark to the coil. Likewise, if the coil is bad it will not give spark to the distributor. Check for spark coming out of the coil. I used a spark plug and grounded it on the valve cover. If you don't have spark one or both is likely your problem.

The coil was $20 so I replaced it (mine had cracks in it) before I did the crank. I still had no spark so I replaced the crank sensor and now it works great.

Good luck!

 

Sorry to hijack this thread. My 99 XJ 4.0 has similar symptoms with a failing CPS. Dies while driving, stalls at idle, all random. I have noticed that it only does it when the heat/blower is on inside the cabin. I am figuring it is either CPS or possible vacuum issues. I don't know when the CPS has been replaced so I figured I should do it anyway. But, didn't know if anyone else noticed that it would stall with the blower on.

Thanks,
Chris